To be asked to prepare a second edition of a book is heartening for any author or editor. Apart from the opportunity to make the corrections and amendments which are inevitable in a practical manual there is also the possibility to make additions which enhance its usefulness. Above all a further edition usually means that the book has been found to be accept able to a large number of readers and has fulfilled a need. This is indeed the case with Offshore Medicine, which in its description of the medical aspects of offshore work has provided a unique guide to the occupational health of a new industry. The rapid development of offshore exploration for gas and oil which began in the 1960s created a whole new range of related industries. Most attention was focused on the problems of deep diving in the North Sea because of the great expansion of the diving industry, its technological advances and the high mortality of divers in the early years. Diving, however, is only a fraction of the total endeavour concerned with the offshore industry. The much larger population of workers offshore who man the rigs and barges, the toolpushers, helicop ter pilots, crane drivers, scaffolders and roustabouts, geologists and so on, so sympathetically described by A. Alvarez in his recent book Off shore, A North Sea Journey, and the harsh and difficult conditions in which they often have to work are sometimes forgotten.